1. Field of the Invention
The invention relates to a pressure or secondary line purging system and method for a mechanical ventilator.
2. Description of the Related Art
Ventilators are commonly used to ventilate a subject's lungs with respiratory gas to assist the subject in breathing. The ventilator may be operatively connected to a subject circuit that is adapted to communicate the flow of gas to an airway of the subject at a subject interface. A pressure line may be operatively connected to the ventilator and may be in fluid communication with the subject circuit at or near the subject interface. A sensor is typically provided that senses the pressure of the flow of gas within the pressure line. The pressure measurements are used to control pressure at the patient, triggering of breaths, and in calculations of parameters in lung mechanics, such as the calculation of work of breathing and lung compliance. The pressure measurements may also be used to assist in controlling the support supplied by a ventilator so as to assist the subject in breathing.
However, during use, the pressure lines may become obstructed with fluid (e.g., water and/or mucous) from the subject. The obstruction may result in erroneous airway pressure readings. Accordingly, there may be insufficient ventilation of the patient. Furthermore, water and/or mucous from the subject may also flow through the pressure line and into the ventilator, which may interfere with the operation of the ventilator.
Conventional purging systems for purging the pressure line of obstruction are known. Conventional purging systems typically include a separate compressor or a secondary source of pressurized gas to purge the pressure lines. Thus, these conventional purging systems may often be bulky, complicated, and expensive to manufacture.